A SpaceX Dragon cargo capsule pulled into port at the International Space Station Wednesday, a day after launch from Florida’s Space Coast with 3.2 tons of experiments, holiday gifts, and external instruments developed by NASA and the U.S. military to help improve hurricane forecasts.
Approaching from above, the unpiloted supply freighter docked with the space station’s Harmony module at 3:41 a.m. EST (0841 GMT) Wednesday, nearly 50 minutes ahead of schedule.
The automated link-up capped a 22-and-a-half hour pursuit of the space station by the reusable Dragon cargo ship, which made its second trip to the complex. After docking more than 260 miles (420 kilometers) above Earth, the Dragon spacecraft’s power and data umbilicals plugged in to the space station’s electrical and communications networks for the mission’s planned 30-day stay.
Astronauts inside the space station planned to open hatches and begin unpacking supplies inside the Dragon capsule’s internal compartment. Meanwhile, the station’s Canadian-built robotic arm will extract two instrument packages carried to the lab inside the spacecraft’s unpressurized trunk for the U.S. military’s Space Test Program.
The delivery was the 24th cargo flight to the space station by SpaceX since 2012. NASA contracted with SpaceX in 2008 for commercial cargo missions to the station, taking over some of the program’s logistics train after the retirement of the space shuttle.
NASA also has a contract with Northrop Grumman for cargo deliveries to the station. Sierra Nevada Corp. aims to begin flying to the station with a cargo vehicle in late 2022 or early 2023.
The latest SpaceX mission carried 6,590 pounds (2,989 kilograms) of supplies and experiments, including packaging, to the research lab’s seven-person crew.
The station crew also received holiday gifts and a feast packed inside the Dragon spacecraft.
“Every year, we do our best to send up some presents to the crew,” said Joel Montalbano, NASA’s space station program manager. “I won’t get in front of Santa Claus and tell you what’s going to be sent up, but we are going have some gifts for the crew.”
The meal includes turkey, green beans, fruit cake, and smoked seafood.
Here’s a breakdown of the cargo load:
• 2,468 pounds (1,119 kilograms) of science investigations
• 2,002 pounds (908 kilograms) of unpressurized payloads
• 852 pounds (386 kilograms) of crew supplies
• 724 pounds (328 kilograms) of vehicle hardware
• 400 pounds (182 kilograms) of spacewalk equipment
• 72 pounds (33 kilograms) of computer resources
The Dragon cargo ship delivered four experimental CubeSats to the station from teams at Kennedy Space Center, Aerospace Corp., Utah State University, and Georgia Tech. The CubeSats will be robotically deployed outside the complex next year.
The scientific experiments on the SpaceX cargo freighter include an investigation from Merck Research Labs studying monoclonal antibodies. The research focus of that experiment is on analyzing the structure and behavior of a monoclonal antibody used in a drug aimed at treating cancers.
Another experiment will assess the loss of immune protection in astronauts flying in space.
Proctor & Gamble and NASA have partnered in another experiment to test the performance of a new fully degradable detergent named Tide Infinity, a product specifically designed for use in space.
Astronauts on the space station currently wear an item of clothing several times, then discard the garment. But crews flying to the moon and Mars won’t have the same supply chain of cargo missions to support them.
NASA says Tide plans to use the new cleaning detergent to “advance sustainable, low-resource-use laundry solutions on Earth.”
Two research pallets from the U.S. military’s Space Test Program are riding inside the Dragon spacecraft’s unpressurized trunk. The two payloads, named STP-H7 and STP-H8, will be transferred from the Dragon spacecraft to mounting points outside the space station using the lab’s robotic arm.
The STP-H7 payload package will be mounted outside the European Space Agency’s Columbus lab module, according to NASA. STP-H8 will be placed on the exposed science facility outside the Japanese Kibo lab.
Two weather instruments from NASA’s Jet Propulsion Laboratory are hosted on the STP-H8 experiment package.
One of them, called the Compact Ocean Wind Vector Radiometer, or COWVR, will measure the direction and speed of winds at the ocean surface. The Temporal Experiment for Storms and Tropical Systems, or TEMPEST, instrument looks at atmospheric humidity, according to NASA.
Scientists will test the instruments’ performance in space during a three-year primary mission. Simultaneous measurements of ocean winds and atmospheric water vapor profiles could improve storm forecasting and weather models.
The COWVR instrument has been in development for a decade. It originally was designed to fly on a standalone military satellite to replace an instrument named WindSat that collects ocean wind data for the Defense Department.
WindSat is on the military’s Coriolis satellite, which has been in orbit since 2003 and is well beyond its design life.
A microwave instrument like COWVR or WindSat measures ocean winds through detecting naturally occurring microwave emissions from Earth’s surface. The microwave data can reveal the speed and direction of winds, useful in applications such as hurricane forecasting and naval deployments.
NASA partnered with the Defense Department in a $24 million program to develop a simplified, new-generation version of the WindSat instrument that can fit within smaller mass and volume constraints. The COWVR instrument weighs 130 pounds (59 kilograms), about an eight the mass of WindSat, and reduces the number of moving parts needed to spin the rotating microwave sensor and collect data.
The new instrument was reassigned from being hosted on its own satellite to a cheaper ride to the space station.
“COWVR has the distinct possibility of being an absolute game changer for our users,” said Don Boucher, principal scientist in the chief architect’s office in the Space Force. “It’s simpler to build, simpler to test, the timeframe to build the instrument is less – so you can build more of them for the same amount of money as one conventional radiometer. That has tremendous implications for our supply chain.”
The TEMPEST radiometer flying alongside COWVR will be sensitive to a different range of microwave signals that yield information about moisture in the atmosphere. The instrument, just the size of a cereal box, is a spare left over from a CubeSat program.
“TEMPEST brings to the table an ability to sense both the amount of atmospheric moisture and its vertical distribution,” said Steve Swadley, the lead for calibration and validation of microwave sensors at the U.S. Naval Research Laboratory in Monterey, California. “This is important both for numerical models and for characterizing the moisture surrounding tropical cyclones.”
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